2,4,5-Trichlorophenol is a grey flake or needle-shaped solid. It is used as an intermediate in the manufacture of the herbicide 2,4,5-Trichlorophenoxyacetic Acid (2,4,5-T) and as a fungicide and bactericide. 2,4,5-trichlorophenol (triclofenol piperazine, Ranestol) is an antifungal agent, which was also used against light hookworm infections. Thirty persons who were positive for hookworm eggs in their stools were treated with 50 mg/kg of triclofenol piperazine dissolved in 5 per cent polyethylene glycol Ranestol® in soft gelatin capsules. Nineteen of these showed 77 to 100 % reduction in egg count average when compared with the pre-treatment counts. Side reactions were limited to mild and transient nausea in 23, vomiting in 7, transient abdominal cramps and headache in 2 each. 2,4,5-trichlorophenol complexed with dicyclohexylamine was used for treatment of experimental mycosis. From the mycological and clinical evaluation the conclusion can be drawn that the effect of phenol in lipophilic ointment is comparable to that of clotrimazole.